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Commit 55b3da98 authored by David Vrabel's avatar David Vrabel
Browse files

xen/balloon: find non-conflicting regions to place hotplugged memory 



Instead of placing hotplugged memory at the end of RAM (which may
conflict with PCI devices or reserved regions) use allocate_resource()
to get a new, suitably aligned resource that does not conflict.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarDaniel Kiper <daniel.kiper@oracle.com>
---
v3:
- Remove stale comment.
parent f5775e0b

drivers/xen/balloon.c

+53 −20
Original line number Original line Diff line number Diff line
@@ -54,6 +54,7 @@ 
#include <linux/memory.h>

#include <linux/memory.h>

#include <linux/memory_hotplug.h>

#include <linux/memory_hotplug.h>

#include <linux/percpu-defs.h>

#include <linux/percpu-defs.h>

#include <linux/slab.h>





#include <asm/page.h>

#include <asm/page.h>

#include <asm/pgalloc.h>

#include <asm/pgalloc.h>
@@ -208,26 +209,56 @@ static bool balloon_is_inflated(void) 
		return false;

		return false;

}

}





static struct resource *additional_memory_resource(phys_addr_t size)

{

	struct resource *res;

	int ret;



	res = kzalloc(sizeof(*res), GFP_KERNEL);

	if (!res)

		return NULL;



	res->name = "System RAM";

	res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;



	ret = allocate_resource(&iomem_resource, res,

				size, 0, -1,

				PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);

	if (ret < 0) {

		pr_err("Cannot allocate new System RAM resource\n");

		kfree(res);

		return NULL;

	}



	return res;

}



static void release_memory_resource(struct resource *resource)

{

	if (!resource)

		return;



	/*

	/*

 * reserve_additional_memory() adds memory region of size >= credit above

	 * No need to reset region to identity mapped since we now

 * max_pfn. New region is section aligned and size is modified to be multiple

	 * know that no I/O can be in this region

 * of section size. Those features allow optimal use of address space and

 * establish proper alignment when this function is called first time after

 * boot (last section not fully populated at boot time contains unused memory

 * pages with PG_reserved bit not set; online_pages_range() does not allow page

 * onlining in whole range if first onlined page does not have PG_reserved

 * bit set). Real size of added memory is established at page onlining stage.

	 */

	 */

	release_resource(resource);

	kfree(resource);

}





static enum bp_state reserve_additional_memory(long credit)

static enum bp_state reserve_additional_memory(long credit)

{

{

	struct resource *resource;

	int nid, rc;

	int nid, rc;

	u64 hotplug_start_paddr;

	unsigned long balloon_hotplug;

	unsigned long balloon_hotplug = credit;



	balloon_hotplug = round_up(credit, PAGES_PER_SECTION);





	hotplug_start_paddr = PFN_PHYS(SECTION_ALIGN_UP(max_pfn));

	resource = additional_memory_resource(balloon_hotplug * PAGE_SIZE);

	balloon_hotplug = round_up(balloon_hotplug, PAGES_PER_SECTION);

	if (!resource)

	nid = memory_add_physaddr_to_nid(hotplug_start_paddr);

		goto err;



	nid = memory_add_physaddr_to_nid(resource->start);





#ifdef CONFIG_XEN_HAVE_PVMMU

#ifdef CONFIG_XEN_HAVE_PVMMU

        /*

        /*
@@ -242,21 +273,20 @@ static enum bp_state reserve_additional_memory(long credit) 
	if (!xen_feature(XENFEAT_auto_translated_physmap)) {

	if (!xen_feature(XENFEAT_auto_translated_physmap)) {

		unsigned long pfn, i;

		unsigned long pfn, i;





		pfn = PFN_DOWN(hotplug_start_paddr);

		pfn = PFN_DOWN(resource->start);

		for (i = 0; i < balloon_hotplug; i++) {

		for (i = 0; i < balloon_hotplug; i++) {

			if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {

			if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {

				pr_warn("set_phys_to_machine() failed, no memory added\n");

				pr_warn("set_phys_to_machine() failed, no memory added\n");

				return BP_ECANCELED;

				goto err;

			}

			}

                }

                }

	}

	}

#endif

#endif





	rc = add_memory(nid, hotplug_start_paddr, balloon_hotplug << PAGE_SHIFT);

	rc = add_memory_resource(nid, resource);



	if (rc) {

	if (rc) {

		pr_warn("Cannot add additional memory (%i)\n", rc);

		pr_warn("Cannot add additional memory (%i)\n", rc);

		return BP_ECANCELED;

		goto err;

	}

	}





	balloon_hotplug -= credit;

	balloon_hotplug -= credit;
@@ -265,6 +295,9 @@ static enum bp_state reserve_additional_memory(long credit) 
	balloon_stats.balloon_hotplug = balloon_hotplug;

	balloon_stats.balloon_hotplug = balloon_hotplug;





	return BP_DONE;

	return BP_DONE;

  err:

	release_memory_resource(resource);

	return BP_ECANCELED;

}

}





static void xen_online_page(struct page *page)

static void xen_online_page(struct page *page)